Association mapping of seed vigor in spring soybean (Glycine max (L.) Merr.) in northeast China
Abstract High-vigor soybean seeds can result in the rapid and uniform emergence of seeds under a wide range of field conditions. We aimed to explore the quantitative trait loci of seed vigor traits and superior allelic and carrier materials from the soybean in northeast China. A total of 257 improved lines and 104 soybean landraces were used to evaluate seed vigor, using normal seedling fresh weight, normal seedling length, main root length, hypocotyl length, and germination percentage, in 2018 and 2019. In this study, the different degrees of LD was detected not only among syntenic markers but also among nonsyntenic ones, suggesting that there had been historical recombination among linkage groups. A total of 19 and 10 simple sequence repeat (SSR) markers associated with seed vigor were detected in improved lines and soybean landraces in 2018 and 2019, respectively. Our results also showed five SSR markers co-associated with two or three vigor traits. In addition, 41 superior alleles and their carrier materials were mined. Based on the elite alleles detected, the best cross combinations for improving seed vigor traits were proposed. The results demonstrate that association mapping is a valuable foundation for molecular breeding for soybean seed vigor.